Oxytocin is an important neurotransmitter, and one which has been implicated in autistic behaviors. Known as the “love hormone,” there’s a lot more to it than that. According to Psychology Today,
It regulates social interaction and sexual reproduction, playing a role in behaviors from maternal-infant bonding and milk release to empathy, generosity, and orgasm. When we hug or kiss a loved one, oxytocin levels increase; hence, oxytocin is often called “the love hormone.” In fact, the hormone plays a huge role in all pair bonding. The hormone is greatly stimulated during sex, birth, and breastfeeding. Oxytocin is the hormone that underlies trust. It is also an antidote to depressive feelings.
As I have noted before, oxytocin has a dark side, meaning low levels of oxytocin not only reduce one’s desires for social interaction, but also reduces the tendency to engage in “groupthink,” the worst versions of which are racism and sexism. To the extent that autistics don’t engage in in-group/out-group thinking, we have a general tendency to not engage in racism and sexism.
However, do note many of the behaviors noted above. I suspect that it’s not just any empathy that’s affected by lower levels of oxytocin, but the specific kind autistics have problems with. Coincidentally, the kind of empathy we autistics have problems with is the same empathy that actually makes people favor their in-groups over out-groups and thus can make people behave in racist and less moral ways.
Also note that oxytocin is as much the sex molecule as the love molecule. I have read that many autistics have little to no interest in sex. While that’s certainly not universal (I’m sure other hormones, etc. are involved and affect sex drive as well), it seems to be much more common among autistics than neurotypicals. Low levels of oxytocin would explain this phenomenon. Ironically, since having sex increases oxytocin levels, those who lack interest in sex due to low oxytocin levels are behaving in such a way as to maintain low oxytocin levels.
The connection to trust is a bit odd to me, as I find autistics to be generally quite trusting. However, it may make sense if trust is tied to in-group members, and distrust to out-group members. Without that distinction, it may be that we are simply more trusting of out-group members, and thus we seem more trusting overall.
Here is an interesting overview of the research to day on the connection between oxytocin and autism. I have also written about the connection between touch and increasing oxytocin levels in a post titled Hugs Help.